1. Field of the Invention
The present invention relates to a refrigerator having an improved recognition rate of RFID tags and, more particularly, to a refrigerator having an improved recognition rate of RFID tags attached to foods stored in storage chambers.
2. Description of the Related Art
Radio Frequency Identification (RFID) is an automatic recognition technique, which recognizes radio frequency, and generally consists of RFID tags, RFID readers, and a host computer. The above RFID technique is employed by noncontact cards, which substitute for barcodes and magnetic cards, and recently has been used in various fields, such as a distribution field (logistics and storage management) and an industrial field (process management).
In addition to the above-described fields, the RFID technique is used in household electric appliances. For example, the RFID technique is employed in refrigerators. A conventional refrigerator, which is disclosed by Japanese Laid-open Publication No. 2002-81848, comprises RFID readers installed in side walls, i.e., left and right walls, and rear walls of storage chambers, a control device performing a food treatment program for treating stored states of foods contained in the storage chambers, and a display unit installed on the outer wall of the refrigerator. In the above conventional refrigerator, RFID tags attached to the foods and the RFID readers communicate with each other at regular intervals of time so as to check the quantity of the stored foods and to display the obtained quantity of the stored foods using the display unit, thereby allowing a user to frequently check whether or not foods are consumed and/or remain.
That is, each of the RFID readers of the conventional refrigerator has a coil-shaped antenna installed therein. The antennas of the RFID readers generate magnetic lines of a designated frequency so that the magnetic lines of the antennas of the RFID readers interlink with those of coil-shaped antennas of the RFID tags. When the antennas of the RFID tags generate electricity due to the interlinking, the RFID tags transmit data regarding the foods, stored in their memories, to the RFID readers using the generated electricity, thereby communicating with the RFID readers.
In order to prevent the generation of a blind area, in which the RFID tags are not recognized, when the RFID tags attached to the stored foods are recognized by the RFID readers, the conventional refrigerator comprises the RFID readers installed in all walls of the storage chambers, thereby having high production costs. For example, in the case that foods are stored in a refrigerator comprising RFID readers installed only in side walls of storage chambers, when loop planes (inner surfaces formed by the turning of the coil-shaped antennas) of coil-shaped antennas of RFID tags attached to the foods are positioned in parallel with the bottom surfaces of the storage chambers, the loop planes of the coil-shaped antennas of the RFID tags are perpendicular to loop planes of the coil-shaped antennas of the RFID readers. Then, magnetic lines generated from the RFID tags are not interlinked with any of magnetic lines generated from the RFID readers. Thus, the RFID readers cannot recognize the RFID tags. Accordingly, the conventional refrigerator is disadvantageous in that the RFID readers must be installed in upper and lower walls of the storage chambers as well as the side walls of the storage chambers.